The present application is directed to electronic manufacturing and more particularly the bonding of a discrete device to a selected location on a substrate.
Anisotropic conductive film (ACF) is an interconnect technology for mechanically and electrically connecting a discrete device to a substrate. Anisotropic conductive films typically consist of a thermosetting resin with embedded conductive particles on a removable liner. The conductive particles are small in relation to the contact pad area of the device and provide z-axis conductivity and are electrically insulating laterally. An existing bonding sequence which uses ACF, involves placing a properly sized piece of ACF, adhesive side down, on to an area of the substrate where the discrete device is to be bonded, applying a light pressure and enough heat for a few seconds to partially cure the adhesive, thereby tacking the ACF into place. The ACF liner is removed and the discrete device is registered to the connecting traces of the substrate. A sufficient temperature and pressure are applied to complete the cure of the adhesive and mechanically compress the conductive particles to make electrical contact. Among other operations, the foregoing requires sizing and transferring the ACF to the substrate, tacking the ACF, removing the protective liner, registering and placing the discrete device and completing the cure operation.
It is considered that more efficient bonding processes and systems which eliminate steps would be useful. Such methods and systems are presented in the following disclosure.